Control system and method for tapered structure construction

ABSTRACT

A control system for forming a tapered structure includes a sensor providing feedback for a machine for forming a tapered structure including at least three rolls having at least one bend roll and at least two guide rolls. The guide rolls may include rollette banks having a plurality of rollettes. The machine may also include an adjustment mechanism to position at least one of the rolls, where a diameter of the tapered structure being formed is controlled by relative positions of the rolls. The machine may also include a joining element to join edges of a stock of material together as it is rolled through the rolls to form the tapered structure. The control system may also include a controller to receive feedback from the sensor and to send a control signal based on the feedback to the adjustment mechanism for positioning at least one of the rolls.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to U.S. patent application Ser. No.13/623,817 filed on Sep. 20, 2012, which claims priority to U.S.Provisional Application No. 61/537,013 filed on Sep. 20, 2011, each ofwhich is hereby incorporated by reference in its entirety.

This application is also related to U.S. patent application Ser. No.12/693,369 filed on Jan. 25, 2010, which is hereby incorporated byreference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under contractDE-SC0006380 awarded by the Department of Energy. The government hascertain rights in the invention.

This invention was made with government support under the NSF SBIR PIaward 1248182 awarded by the National Science Foundation. The governmenthas certain rights in the invention.

TECHNICAL FIELD

This document generally relates to a control system for taperedstructure construction, and a method for controlling the machinery forconstructing tapered structures.

BACKGROUND

Various techniques and devices exist that can produce taperedstructures, such as cones or frusto-conical structures. One generalapproach to constructing tapered structures involves bending orotherwise deforming metal stock in desired ways, then joining the stockeither to itself at certain points, or joining the stock to otherstructures at certain points. The control systems for such techniques donot facilitate the substantially continuous and accurate construction ofa tapered structure, for example, a tapered structure for use as a windturbine tower.

Spiral welding machines exist that form continuous diameter tubes, forexample, for pipes and the like. These machines may include controlsystems where an operator adjusts a parameter of the spiral weldingmachine based on a measurement of the tube diameter. However, themanufacture of a tapered structure has additional difficult-to-controldegrees of freedom and hence there exists a need for a control systemand method for tapered structure construction where the machinery forforming tapered structures is adjusted continuously and automatically tocreate a substantially error free tapered structure.

SUMMARY

In general, in one aspect, a control system for forming a taperedstructure includes a sensor providing feedback for a machine for forminga tapered structure. The machine for forming a tapered structure mayinclude at least three rolls including at least one bend roll and atleast two guide rolls. The guide rolls may include rollette banks havinga plurality of rollettes. The machine for forming a tapered structuremay also include an adjustment mechanism configured to position at leastone of the rolls, where a diameter of the tapered structure being formedis controlled by relative positions of the rolls. The machine forforming a tapered structure may also include a joining elementconfigured to join edges of a stock of material together as the stock ofmaterial is rolled through the rolls to form the tapered structure. Thecontrol system may also include a controller configured to receivefeedback from the sensor and to send a control signal based on thefeedback to the adjustment mechanism for positioning at least one of therolls.

In general, in another aspect, a control system for forming a taperedstructure includes a sensor providing feedback for a machine for forminga tapered structure. The machine for forming a tapered structure mayinclude at least three rolls including at least one bend roll and atleast two guide rolls. The guide rolls may include rollette banks havinga plurality of rollettes. The machine for forming a tapered structuremay also include an infeed adjustment mechanism configured to position astock of material as it is fed into the rolls, where the stock ofmaterial forms the tapered structure as it is rolled through the rolls.The machine for forming a tapered structure may also include a joiningelement configured to join edges of the stock of material together asthe stock of material is rolled through the rolls to form the taperedstructure. The control system may also include a controller configuredto receive feedback from the sensor and to send a control signal basedon the feedback to the infeed adjustment mechanism for positioning thestock of material as it is fed into or through the machine for forming atapered structure.

In general, in yet another aspect, a control system for forming atapered structure includes an edge position sensor configured to providefeedback including a position of an edge of a stock of material to beformed into a tapered structure in a machine for forming a taperedstructure. The machine for forming a tapered structure may include arolling assembly having a plurality of rolls, a joining elementconfigured to join edges of the stock of material together as the stockof material is rolled through the rolling assembly to form the taperedstructure, a runout system configured to support the tapered structureafter the edges are joined, and an adjustment mechanism configured toposition the tapered structure relative to the rolling assembly. Thecontrol system may also include a controller configured to receivefeedback from the edge position sensor and to send a control signalbased on the feedback to the adjustment mechanism to achieve a desiredrelative movement between portions of the tapered structure.

In general, in another aspect, a control system for forming a taperedstructure includes a model for use in a machine for forming a taperedstructure. The machine for forming a tapered structure may include atleast three rolls including at least one bend roll and at least twoguide rolls. The guide rolls may include rollette banks having aplurality of rollettes. The machine for forming a tapered structure mayalso include an adjustment mechanism configured to position at least oneof the rolls, where a diameter of the tapered structure being formed iscontrolled by relative positions of the rolls. The machine for forming atapered structure may further include a joining element configured tojoin edges of a stock of material together as the stock of material isrolled through the rolls to form the tapered structure. The model mayinclude relative positions of the rolls for desired tapered structurediameters. The control system may also include a computer configured toimplement the model, and a controller configured to receive instructionsbased on the model and to send a control signal based on theinstructions to the adjustment mechanism for positioning at least one ofthe rolls.

In general, in yet another aspect, a control system for forming atapered structure includes a model for use in a machine for forming atapered structure. The machine for forming a tapered structure mayinclude at least three rolls including at least one bend roll and atleast two guide rolls. The guide rolls may include rollette banks havinga plurality of rollettes. The machine for forming a tapered structuremay also include an infeed adjustment mechanism configured to position astock of material as it is fed into the rolls, where the stock ofmaterial forms the tapered structure as it is rolled through the rolls.The machine for forming a tapered structure may further include ajoining element configured to join edges of the stock of materialtogether as the stock of material is rolled through the rolls to formthe tapered structure. The model may include relative positions of thestock of material as it is fed into or through the machine for forming atapered structure. The control system may also include a computerconfigured to implement the model, and a controller configured toreceive instructions based on the model and to send a control signalbased on the instructions to the infeed adjustment mechanism forpositioning the stock of material.

In general, in another aspect, a method for controlling the formation ofa tapered structure includes sensing with a sensor, on a system forforming a tapered structure, at least one of a geometric attribute ofthe tapered structure being formed and a force attribute of the taperedstructure being formed. The system for forming a tapered structure mayinclude at least three rolls including at least one bend roll and atleast two guide rolls. The guide rolls may include rollette banks havinga plurality of rollettes. The system for forming a tapered structure mayalso include an adjustment mechanism configured to position at least oneof the rolls, where a diameter of the tapered structure being formed iscontrolled by relative positions of the rolls. The system for forming atapered structure may further include a joining element configured tojoin edges of a stock of material together as the stock of material isrolled through the rolls to form the tapered structure. The method mayalso include: sending feedback from the sensor to a controller, wherethe feedback is based on at least one of the geometric attribute and theforce attribute; sending adjustment instructions from the controller tothe adjustment mechanism, where the adjustment instructions are based onthe feedback; and adjusting a position of at least one of the rolls withthe adjustment mechanism based on the adjustment instructions.

In general, in yet another aspect, a method for controlling theformation of a tapered structure includes sensing with a sensor, on asystem for forming a tapered structure, a position of a stock ofmaterial for forming into the tapered structure. The system for forminga tapered structure may include at least three rolls including at leastone bend roll and at least two guide rolls. The guide rolls may includerollette banks having a plurality of rollettes. The system for forming atapered structure may also include an infeed adjustment mechanismconfigured to position the stock of material as it is fed into at leastone of the rolls, where the stock of material forms the taperedstructure as it is rolled through the rolls. The system for forming atapered structure may further include a joining element configured tojoin edges of the stock of material together as the stock of material isrolled through the rolls to form the tapered structure. The method mayalso include: sending feedback from the sensor to a controller, wherethe feedback is based on the position of the stock of material; sendingadjustment instructions from the controller to the infeed adjustmentmechanism, where the adjustment instructions are based on the feedback;and adjusting with the adjustment mechanism the position of the stock ofmaterial as it is fed into or through the system for forming a taperedstructure based on the adjustment instructions.

In general, in another aspect, a method for controlling the formation ofa tapered structure includes sensing with an edge position sensor, on asystem for forming a tapered structure, a position of an edge of a stockof material to be formed into the tapered structure. The system forforming a tapered structure includes: a rolling assembly having aplurality of rolls; a joining element configured to join edges of thestock of material together as the stock of material is rolled throughthe rolling assembly to form the tapered structure; a runout systemconfigured to support the tapered structure after the edges are joined;and an adjustment mechanism configured to position the tapered structurerelative to the rolling assembly. The method may also include: sendingfeedback from the edge position sensor to a controller, where thefeedback is based on the position of the edge of the stock of material;sending adjustment instructions from the controller to the adjustmentmechanism, where the adjustment instructions are based on the feedback;and adjusting a position of the tapered structure relative to therolling assembly using the adjustment mechanism based on the adjustmentinstructions.

In general, in yet another aspect, a method for controlling theformation of a tapered structure includes: driving a stock of materialwith an infeed system; feeding the stock of material through a rollingassembly having at least three rolls including at least one bend rolland at least two guide rolls, where the guide rolls include rollettebanks having a plurality of rollettes; joining edges of the stock ofmaterial together as the stock of material is rolled through the rollingassembly to form a tapered structure; guiding the stock of material outof the rolling assembly with a runout system; and sensing, with asensor, sensor data including at least one of (i) a geometric attributeof the tapered structure being formed, (ii) a force attribute of thetapered structure being formed, (iii) a position of the stock ofmaterial, (iv) an inconsistency in a weld gap in the stock of material,(v) a planar alignment error in the stock of material, and (vi) anangular alignment error in the stock of material. The method may alsoinclude: sending feedback from the sensor to a controller, where thefeedback is based on the sensor data; sending adjustment instructionsfrom the controller to an adjustment mechanism, where the adjustmentinstructions are based on the feedback; and adjusting a position of thestock of material using the adjustment mechanism based on the adjustmentinstructions.

Other implementations of any of the foregoing aspects can be expressedin various forms, including methods, systems, apparatuses, devices,computer program products, products by processes, or other forms. Otheradvantages will be apparent from the following figures and description.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of the systemsand methods described herein will be apparent from the followingdescription of particular embodiments thereof, as illustrated in theaccompanying drawings. The drawings are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thesystems and methods described herein.

FIG. 1 is a block diagram of a construction system for forming taperedstructures.

FIG. 2 is a schematic depiction of a triple roll.

FIG. 3 is an isometric view of a rollette bank.

FIGS. 4A and 4B are top views of a rollette bank.

FIG. 5A is an isometric view of a construction system for formingtapered structures.

FIG. 5B is a top view of a construction system for forming taperedstructures.

FIG. 6 is an isometric view of a curving device.

FIG. 7 is a plot showing a relationship between rollette bank positionsand a resulting radius of curvature of a tapered structure being formed.

FIG. 8 is a schematic depiction of a triple roll.

FIG. 9 is a top view of a structure with gap errors and a structurewithout gap errors.

FIG. 10 is a top view of a structure formed by feeding material atdifferent angles.

FIGS. 11A and 11B are schematic depictions of sheet steering.

FIGS. 12A and 12B are schematic illustrations of an in-plane gap error.

FIGS. 13A and 13B are schematic illustrations of an out-of-plane gaperror.

FIGS. 14A and 14B are schematic illustrations of a tangency alignmenterror.

FIG. 15 is a close-up view of an inboard subsystem.

FIG. 16 is a close-up view of an outboard subsystem.

FIG. 17 is a flow chart of a method for weld gap adjustment.

FIG. 18 is a block diagram for a control system.

FIG. 19 is a flow chart of a method for controlling the formation of atapered structure.

FIG. 20 is a flow chart of a method for controlling the formation of atapered structure.

FIG. 21 is a flow chart of a method for controlling the formation of atapered structure.

FIG. 22 is a flow chart of a method for forming a tapered structure.

FIG. 23 is a schematic depiction of a solid roller and a rollette bank.

Like references numbers refer to like structures.

DETAILED DESCRIPTION

The embodiments will now be described more fully hereinafter withreference to the accompanying figures in which preferred embodiments areshown. The system and methods described herein may, however, be embodiedin many different forms and should not be construed as limited to theillustrated embodiments set forth herein. Rather, these illustratedembodiments are provided so that this disclosure will convey the scopeto those skilled in the art.

All documents mentioned herein are hereby incorporated in their entiretyby reference. References to items in the singular should be understoodto include items in the plural, and vice versa, unless explicitly statedotherwise or clear from the text. Grammatical conjunctions are intendedto express any and all disjunctive and conjunctive combinations ofconjoined clauses, sentences, words, and the like, unless otherwisestated or clear from the context. Thus, the term “or” should generallybe understood to mean “and/or” and so forth.

Recitation of ranges of values herein are not intended to be limiting,referring instead individually to any and all values falling within therange, unless otherwise indicated herein, and each separate value withinsuch a range is incorporated into the specification as if it wereindividually recited herein. The word “about,” “approximately,” and thelike, when accompanying a numerical value, is to be construed asindicating a deviation as would be appreciated by one of ordinary skillin the art to operate satisfactorily for an intended purpose. Ranges ofvalues and/or numeric values are provided herein as examples only, anddo not constitute a limitation on the scope of the describedembodiments. The use of any and all examples, or exemplary language(“e.g.,” “such as,” or the like) provided herein, is intended merely tobetter illuminate the embodiments and does not pose a limitation on thescope of the embodiments. No language in the specification should beconstrued as indicating any unclaimed element as essential to thepractice of the embodiments.

In the following description, it is understood that terms such as “top,”“bottom,” “above,” “below,” “first,” “second,” “up,” “down,” “left,”“right,” and the like, are words of convenience and are not to beconstrued as limiting terms.

It is often desirable to form a tapered structure, such as a conical orfrusto-conical structure, from a substantially planar stock withoutintroducing substantial in-plane deformation to the stock. For example,U.S. patent application Ser. No. 12/693,369, entitled “TAPERED SPIRALWELDED STRUCTURE,” discusses some applications of such structures.Additionally, U.S. patent application Ser. No. 13/623,817, entitled“TAPERED STRUCTURE CONSTRUCTION,” discusses some construction systemsfor such structures. Among other things, the techniques described belowcan be used in conjunction with the systems, devices, and methodsdescribed in these applications, both of which are incorporated byreference in their entirety. Additionally, the control systems andmethods described herein may be used in addition to, in conjunctionwith, or in replacement of any controls described in these applications.

FIG. 1 is a block diagram of a construction system. The system 100includes a stock material source 102 (which may be metal), an infeedsystem 104, a curving device 106, a joining element 108, a runout system110, and a control system 112. As described more fully herein, thesystem 100 is operable to construct tapered structures. In one aspect,the control system 112 controls at least one of the stock materialsource 102, infeed system 104, curving device 106, joining element 108,and runout system 110. However, one skilled in the art will appreciatethat in other aspects the control system 112 may control more or lesscomponents of the construction system 100, and any combinations thereof.In addition, the components, or combinations thereof, may includeindividual controls/control systems, where in one aspect the controlsystems are in communication with one another.

The stock material source 102 may include the raw metal from which atapered structure is formed. In some implementations, the stock materialsource 102 can include a collection of planar metal sheets, dimensionedin any of the ways described in U.S. patent application Ser. No.12/693,369, a roll of stock material, or the like. The sheets can beconstructed and arranged to facilitate easily picking a desired sheet inthe manufacturing process. For example, the sheets can be stored in amagazine or other suitable dispenser. As used throughout thisdisclosure, the “stock,” “stock of material,” “sheet”, and the like,shall refer to the material to be formed into the tapered structureunless explicitly stated otherwise or clear from the text. As discussedabove, in some implementations the stock can include a roll of metal orother material. In some implementations the stock comprises pre-cutindividual sheets.

The infeed system 104 is operable to transport metal from the stockmaterial source 102 to (and in some implementations, through) thecurving device 106. The infeed system 104 can include any suchappropriate equipment for transporting a desired sheet according totraditional techniques. Such equipment can include, for example, roboticarms, pistons, servos, screws, actuators, rollers, drivers,electromagnets, or the like, or combinations of any of the foregoing. Asdescribed herein, a control system may include an infeed control systemthat includes controls for feeding the stock material into the curvingdevice 106 in such a manner that a desired tapered structure can beformed.

The curving device 106 is operable to curve the material fed into it,and in one aspect, without imparting any in-plane deformation to thematerial. Moreover, the curving device 106 can impart a controllabledegree of curvature to the material. In an implementation, the curvingdevice includes a plurality of rolls. Rolls as described herein mayinclude, but are not limited to, rollers (including substantiallycylindrical rollers, substantially cone-shaped rollers,irregularly-shaped rollers, spherical rollers, or the like), a rollettebank that includes a plurality of rollettes (e.g., smaller rollers,wheels, bearings, spherical rollers, or the like) that collectivelyapproximate the exterior of the corresponding solid structure, or anyother element that may be used to bend/roll/manipulate a stock ofmaterial into a tapered structure. The curving device 106 may include atriple roll 200 as shown schematically in FIG. 2 (described in moredetail below). As used throughout this disclosure, the “curving device,”“rolling assembly,” “triple roll,” and the like, shall refer to anydevice or component operable to curve the material fed into it (e.g., asdescribed herein), unless otherwise stated or clear from the context.

The joining element 108 is operable to join sheets of in-fed stock toother sheets of in-fed stock (or to themselves, or to other structures).In some implementations, the joining element 108 is a welder thatincludes one or more weld heads whose position and operation iscontrollable by a control system. In general, the joining element 108may include any component or machine for joining the stock by any knownmeans, including welding, adhesives, epoxy, crimps, rivets, bolts,fasteners, complementary geometric features (e.g., pins that mate withholes, teeth that mate with each other, snaps, etc.), and the like. Thejoining element 108 may be configured to join edges of the stock ofmaterial together as the stock of material is rolled through the curvingdevice 106. In some implementations, there may be multiple joiningelements and/or multiple steps for joining edges of the stock ofmaterial together. For example, for trapezoidal shaped sheets of stockhaving a pair of long sides and a pair of short sides, the short sidesmay be joined first (e.g., with other sheets of stock), then the stockdeformed, and then the long sides joined.

The runout system 110 is operable to transport material from the curvingdevice 106 and joining element 108 (i.e., the structure taking form orbeing formed). This may involve supporting, holding, transporting,moving, guiding, manipulating, pushing, pulling, twisting, etc., thestructure being formed. The runout system 110 can include any suchappropriate equipment according to traditional techniques. Suchequipment can include, for example, robotic arms, pistons, servos,screws, actuators, rollers, drivers, electromagnets, subsystems, or thelike, or combinations of any of the foregoing. As described herein, acontrol system may include a runout control system that includescontrols for supporting and positioning the tapered structure beingformed after the edges of the stock of material are joined.

The control system 112 is operable to control and coordinate the varioustasks described herein, including, but not limited to, operating theinfeed system 104, operating the curving device 106, operating thejoining element 108, and operating the runout system 110. The controlsystem 112 may include computer hardware, software, circuitry, or thelike that can collectively generate and deliver control signals to thecomponents and systems described herein to accomplish the desired tasks.

The control systems and methods described herein can generally be usedfor any of the construction machinery described herein including themachinery and systems described in the references incorporated byreference in their entirety herein. In general, a “control system” mayrefer to an individual control system for an individual component/pieceof machinery, or to a combination of control systems, or to a controlsystem that controls numerous components/pieces of machinery and/orsystems.

As discussed herein, it may be desirable to arrange for the stock beingfed into system 100 to undergo a purely rotational motion during theinfeed process. Specifically, the purely rotational motion may takeplace as the stock is fed into the curving device 106. The controlsystems and methods described herein may be designed to achieve thisfunction.

Although the phrase “purely rotational” motion has been used, slightdeviations from pure rotation (i.e., slight translations of the stock orpeak relative to each other) may be permissible. If the stock undergoesany translational motion with respect to the peak during the infeedprocess, the resultant structure may deviate from an idealfrusto-conical geometry. In particular, there may be gaps where thestock fails to meet corresponding edges of predecessor portions ofstock, the stock may overlap itself, or both. Therefore, a controlsystem as described herein may control the stock of material to preventtranslational motion relative to the peak. However, slight translationalmotion may be acceptable, e.g., if the gap is kept within an acceptablerange.

As used in this document, “substantially rotational” motion means purelyrotational motion as described above, except for allowing for slightdeviations that may be useful later in the manufacturing process, or beacceptable because the structure geometry can still be kept within adesired range/tolerance, or that are small enough to not detrimentallyaffect cone geometry, buckling strength, fatigue strength, etc. Thedegree of these permissible deviations, in general, will vary with thedimensions of the desired frusto-conical structure and the manufacturingsteps that the deviations accommodate. Also as used in this document,“rotational motion” should be understood to mean either substantiallyrotational motion or purely rotational motion.

A triple roll will now be described.

FIG. 2 represents a simple schematic of how a basic triple roll 200 mayoperate. The triple roll 200 may include three substantially cylindricalrollers 204 that are substantially parallel to one another and that areoperable to impart a curvature to a stock of material 202 fed throughthe rollers 204 in the direction of the dashed arrow 206. The tripleroll may also or instead include one or more banks of rollettes that areoperable to impart a curvature to the stock of material in the samemanner as solid rollers 204. The degree of curvature can be controlledby, e.g., dynamically adjusting the relative positions of the rollers204 or rollette banks, etc.

FIGS. 3, 4A and 4B show an example of a rollette bank with a rollettesteering mechanism including cam plate steering. Specifically, FIG. 3shows an example of a rollette bank 300. As shown in FIG. 3, therollette bank 300 may include a plurality of rollettes 302. Therollettes 302 may include rollers whose axes of revolution areadjustable with respect to other axes of revolution in a triple roll.The rollettes 302 may be steered using a cam plate steering system asdescribed below. The rollettes 302 may include a roller 304 (e.g., acylindrical roller, spherical roller, sliding pad, and so forth) and abody 306 or housing that may support/hold the roller 304. The rollettebank 300 may also include a base 308, where the body 306 may interfacewith the base 308 thereby coupling the rollettes 302 to the rollettebank 300, e.g., in a manner that permits rotation relative to the base308 of the rollette bank 300. One of ordinary skill will recognize thatthere are other means for connecting the rollettes 302 to the rollettebank 300.

The rollette bank 300 may also include a rollette steering mechanism.The rollettes 302 may interface with the rollette steering mechanism,where such an interface may be made possible by the body 306 or the base308 of the rollette bank 300. The steering mechanism may include,without limitation, cams, a four-bar linkage or other linkages,individual steering actuators, and the like. For example, FIG. 3 shows arollette steering mechanism that includes a steering actuator 310 thatdrives a steering cam plate 312, which in turn can steer the rollettes302. The rollette steering mechanism may also or instead include anyform of a rollette adjustment mechanism configured to position angles ofthe rollettes 302 on the rollette bank 300.

FIGS. 4A and 4B show a rollette bank 400 with a rollette steeringmechanism. The rollette bank 400 includes rollettes 402 having rollers404 and a roller housing 406. The rollette bank 400 shown in FIGS. 4A-Balso includes a base 408. As best shown in FIG. 4B, the rollettesteering mechanism may include a cam plate actuator 410 configured tomove a cam plate 412 in at least the directions shown by the arrows 414.The rollettes 402 may be engaged with the cam plate 412 by any meansknown in the art, including, without limitation, via a rollette arm 416including a cam mating pin 418 that connects to the cam plate 412through a corresponding cam slot 420. The cam mating pin 418 may insteadbe replaced by a roller, cam follower, and the like. The cam slots 420may be cut into configurations such that when the cam plate 412 ismoved, the geometry of the cam slots 420 causes the cam mating pins 418to move, thereby rotating the rollettes 402. The cam slots 420 in thecam plate 412 may all be the same, or they may be different for eachrollette 402. If the rollettes 402 are identical to each other, and thecam slots 420 on the cam plate 412 are the same, then the rollettes 402will move together and will be at substantially the same angle. If therollettes 402 are different from each other (i.e., if the angle of therollette arm 416 relative to the roller axis varies between rollettes402) and the cam slots 420 in the cam plate 412 are the same, then therollettes 402 will move together but may be at different angles fromeach other. If the cam slots 420 in the cam plate 412 are different forone or more rollettes 402, then the movement of the rollettes 402 willhave some correspondence (i.e., from the geometry of the cam slot 420)but they won't necessarily move together. For example, the cams could beconstructed such that some rollettes don't move at all, while othersrotate. A skilled artisan will recognize that many configurations arepossible.

The cam plate 412 itself may be actuated relative to the rollettes 402in order to rotate the rollettes 402. The cam plate 412 may be guided orheld in place by any known means, including, without limitation, a camplate hold down 422 and a cam plate guide 424, or slides, bearings,rollers, pins, linkages, etc. Activating the cam plate actuator 410 maymove the cam plate 412 in the direction shown by the arrows 414, whichin turn, due to the coupling of the rollette arm 416 and the cam plate412, rotates the rollettes 402, for example, along the axis of rotation426 indicated in FIG. 4A. The cam plate 412 may be actuated by any meansknown to a skilled artisan including, without limitation, electricmotors, pneumatics, hydraulics, etc.

A control system for rolling a stock of material and forming a taperedshape with a substantially continuously changing diameter, and themachine components thereof, will now be discussed. As used throughoutthis disclosure, a structure with a “substantially continuously”changing diameter shall refer generally to a tapered structure such as acone, truncated cone, or the like. Similarly, as used throughout thisdisclosure, “substantially continuously” adjusting a diameter (or thelike) shall refer to generally creating a tapered structure such as acone, truncated cone, or the like. As will be recognized by a skilledartisan, a tapered structure may include either an actual peak or avirtual peak. An actual peak is a point at which the diameter eventuallydecreases to zero. For example, a cone has an actual peak at its apex.For a truncated structure, such as a frusto-conical structure, a“virtual peak” is the point at which the diameter would eventuallydecrease to zero if the structure were not truncated. As used herein,the word “peak” includes both actual peaks and virtual peaks.

An implementation of a machine for forming a tapered structure is shownin FIGS. 5A-6, which will now be described in more detail.

FIGS. 5A and 5B depict a construction system 500 for forming taperedstructures according to an embodiment, where FIG. 5A shows an isometricview of the system 500 and FIG. 5B shows a top view of the system 500.Specifically, FIGS. 5A-B show a construction system 500 for formingtapered structures from a stock of material 501, such as a truncatedcone 502 that can be used as a wind turbine tower. As used throughoutthis disclosure, the “tapered structure,” “cone,” truncated cone,” andthe like, shall refer to a structure formed by the devices, systems, andmethods described herein. The system 500 may include a plurality ofsubsystems, including a stock material source (not shown), an infeedsystem 504, a curving device 506, a joining element (not shown), acontrol system (not shown), and a runout system 508.

The infeed system 504 is operable to perform a function including,without limitation, feeding, transporting, guiding, forcing,positioning, etc., a stock of material 501 to (and in someimplementations, through) the curving device 506. As shown in FIGS.5A-B, the infeed system 504 may include a drive roll 510 with infeedrollers 512, and an infeed actuator 514. The components of the infeedsystem 504 may be supported by an infeed base 528, which may include aframe, which may be positionable. The drive roll 510 may feed the stockof material 501 into the curving device 506, and the drive roll 510 maysteer the stock of material 501 into the curving device 506. Thesteering of the stock of material 501 may be enabled by the infeedactuator 514, which is able to adjust at least one of a position of thestock of material 501, a position of the drive roll 510, a position ofthe infeed rollers 512, a position of the infeed base 528, and aposition of the entire infeed system 504. The infeed actuator 514 mayalso be able to adjust an angle of the aforementioned components in animplementation. Other configurations of the infeed system 504 arepossible, including embodiments with a singular drive roll (which maynot be a “roll” at all), implementations with more or less actuators, orimplementations with other means for providing an adjustment mechanismfor the infeed system 504. In general, the infeed system 504 may includea drive roll adjustment mechanism configured to adjust a position andangle of the drive roll 510. A combination of an infeed adjustmentmechanism and the drive roll adjustment mechanism may position the stockof material 501. In an implementation, the infeed system 504 may impartno constraint on the stock's motion, and the stock of material 501 neednot rotate with respect to any other point in the infeed system 504.

The curving device 506 may generally include a triple roll 516 with atop roll 518 and two bottom rolls 520. The rolls of the triple roll 516may generally include a rollette bank 522 that includes a plurality ofrollettes 524, which may be in the form of rollers.

The infeed system 504 and the curving device 506 may be supportedseparately on their own frames, or may be on a single frame which allowsthe infeed system 504 and the curving device 506 to move together (notshown). Alternatively, either or both of the infeed system 504 and thecurving device 506 may be stationary. Also, either or both of the infeedsystem 504 and the curving device 506 may be able to move independently.The supports (and/or a single frame in an embodiment not shown) may beadjustable with many degrees of freedom, e.g., in a direction parallelto the central axis of the truncated cone 502 (the x-direction, i.e.,toward and away from the peak 503 of the cone 502), in a directionnormal to the central axis of the cone 502 (the y-direction, i.e.,toward and away from the tracks 526 of the runout system 508), up anddown, (the z-direction) and rotating about the x, y and z axes, and torotate the frame about various axes (e.g., if adjusting roll positionrather than run-out position for gap control). The movement of thesecomponents may be accomplished through means known by skilled artisans,including, without limitation, hydraulic pistons, pneumatic pistons,servos, screws, actuators, rack and pinion systems, cable and pulleysystems, cams, electromagnetic drives, robotic arms, rollers, drivers,or the like, or combinations of any of the foregoing or other devicescapable of imparting the desired motion. Moreover, although notdescribed herein, subsystems of the components shown may be mobile(e.g., certain arms and supports may be positionable in any manner askilled artisan might envision).

FIG. 6 is a close up view of an implementation of the curving device600, i.e., the roll forming system. As described herein, in someembodiments, the curving device 600 includes a triple roll 602. Thetriple roll 602 may include a top roll 604, and two bottom rolls 606 (orconversely a bottom roll and two top rolls—not shown). The top roll 604may be articulated vertically—either manually, or under the direction ofa curving device control system or other control system. Articulatingthe top roll 604 can be useful, for example, to engage the stock ofmaterial, or to control the amount of curvature imparted to the stock ofmaterial as it passes through the triple roll 602. The bottom rolls 606can also or instead be articulated, for example, along sloped surfaces608 that support the bottom rolls 606, along another sloped surface orpath, or along a curved surface or path. Moving the bottom rolls 606 maybe done for the same or similar purposes as moving the top roll 604,e.g., to make it easier to start feeding the stock of material, and tocontrol the diameter of the tapered structure being formed. In general,any of the rolls of the triple roll 602 can be articulated, and anycontrollable change in the relative position of the rolls can be used toimpart corresponding amounts of curvature to the stock of material.

In some implementations, and as described above, the triple roll 602includes a plurality of individual rollettes 610 arranged in banks. Ingeneral, banks of rollettes may allow the direction of travel of thestock of material through the triple roll to be at an angle other thanperpendicular to the axis of bending as the stock of material is rolled.For example, in a triple roll with three solid rolls, the direction ofthe axis of bending is basically parallel to the axes of the rolls, andthe stock of material is compelled by the rotation of the rolls to movein a direction perpendicular to this direction, so that the stock ofmaterial is forced to roll back on itself. Very large side forces may beneeded to change this orientation. For the purposes of continuouslyrolling a cylindrical or tapered shape, the stock of material should beable to be fed in to the triple roll at an angle that may allow thestock of material to be formed into a helix, where rollette banks may beutilized to allow this to occur.

When banks of rollettes are used, the bend axis may still besubstantially parallel to the orientations of the rollette banks, whilethe stock of material may be compelled to move in the direction of therollettes. To demonstrate a difference between the use of a solid rollerand the use of rollette banks, FIG. 23 shows a first configuration 2300with a solid roller 2302. In the first configuration 2300, the stock ofmaterial 2304 is fed through the solid roller 2302 in a first feeddirection 2306, which may be normal to the bend axis 2308. This mayproduce a first bent roll 2310 similar to that shown above the firstconfiguration 2300 (i.e., the direction of the bend axis 2308 issubstantially parallel to the axis of the solid roller 2302, and thestock of material 2304 is compelled by the rotation of the solid roller2302 to move in a direction perpendicular to this direction, so that thestock of material 2304 is forced to roll back on itself as shown by thefirst bent roll 2310). Alternatively, as shown in the secondconfiguration 2312, the angle of the rollettes 2316 on the rollette bank2314 may be independent of the position of the rollette bank 2314. Thestock of material 2318 thus may be fed at any angle relative to the bendaxis 2320 as long as the direction of the stock of material 2318 isgenerally along the rolling direction of the rollettes 2316. Thus, itmay be advantageous to have the heading of the rollettes 2316 beindependent of the direction of the bend axis 2320—the system may havethe same bend axis 2320, but rotate the rollettes 2316 such that thein-feed angle can change, which changes the angle of the helix formed byrolling the stock of material 2318. For example, the stock of material2318 may be fed along the second feed direction 2322. This may produce asecond bent roll 2324 similar to that shown above the secondconfiguration 2312, i.e., more of a helix shape than the first bent roll2310 produced by the first configuration 2300. This may be advantageousfor substantially continuous rolling and welding processes, where thestock of material is fed into the rolling machine at a desired angle,and is formed into what is more or less a helix (i.e., it may be a helixfor cylinders, and may be a helix-like structure for cones) that is thenjoined into a solid shape.

In various implementations, the rolls can be individually driven, drivencollectively, or not driven at all. Similarly, in variousimplementations, the rollettes can be individually driven, drivencollectively, or not driven at all. The rollettes may also beindividually steered, steered collectively, or not steered at all. In anembodiment, the banks are substantially parallel. In another embodiment,the banks need not be parallel.

Turning back to FIG. 6, in an implementation, the bottom rolls 606 arelower rollette banks, which are movable in both translation and angle.That is, the bottom rolls 606 can be moved closer and farther apartwhile remaining parallel, and their relative angle can also be changed,so that, for example, the distance between corresponding rollettes 610of each rollette bank near the throat 612 of the curving device 600 canbe greater than the distance between corresponding rollettes 610farthest away from the throat 612. This may assist the system in formingtapered structures, and in controlling the diameter and taper of thestructure being formed. In the implementation shown in FIG. 6, theactuation of the rollette banks is done with four screw jacks 614 drivenby electric motors, with the rollette banks sliding on a low-frictionsurface 616 between sets of guides 618. A skilled artisan will recognizethat other means for moving the rollette banks are possible, forexample, the rollette banks could also be guided by profile rails, othertypes of rails, slides, bushings, linkages, and the like, and theactuation could be done with ball screws, screw jacks, rack and pinions,belts, pistons, and the like.

The relationship between the roll position (e.g., rollette bankposition) and the resulting radius of curvature of the tapered structurebeing formed will now be discussed.

FIG. 7 shows an example of model results predicting rolled diameter fora given distance between lower rollette banks, e.g., the bottom rolls802 of FIG. 8. Specifically, FIG. 7 represents a plot 700 where thestock of material is approximately 0.075″ thick steel with anapproximate yield strength of 50 ksi. For example, this model 700,likely along with empirical adjustments made based on testing results,could be used as the basis for a control system that continuouslycontrols the diameter of the tapered structure being formed bysubstantially continuously adjusting the positions of the rollette banksof a triple roll. This control system could be used with or without anadditional feed-back system

Specifically, FIG. 7 shows a plot 700 that includes example modelresults for the relationship between the rollette bank positions and theresulting radius of curvature of the tapered structure being formed. Theplot 700 includes the distance between the bottom rolls (e.g., lowerrollette banks) in a triple roll along the x-axis, where the x-axisincludes a distance from 7-13 inches. The plot 700 further includes theradius of curvature of the tapered structure being formed along they-axis, where the y-axis includes a radius of curvature from 0-20inches.

FIG. 8 is a diagram that represents the rolls in a triple roll 800,including two bottom rolls 802 and a top roll 804, where the rolls maybe rollette banks. The first and second arrows 806, 808 represent thebottom rolls 802 moving away from each other along sloped surfaces 810,812. The first double arrow 814 represents the distance between thebottom rolls 802. The second double arrow 816 represents the distancebetween the bottom rolls 802 and the top roll 804.

As stated above, in an implementation, the degree of imparted curvaturefrom the curving device (e.g., the triple roll) may be controlledcontinuously. To form a conical or frusto-conical structure, forexample, the curvature with which a given point on the in-coming stockof material is deformed may vary linearly with the height along theresultant cone's axis at which the given point will lie. Other taperedstructures may include other degrees of imparted curvature. FIGS. 7 and8 show a way in which the rolls or rollette banks of the triple roll canbe adjusted to control the tapered structure diameter. In animplementation, the top roll 804 is fixed in place, and the two bottomrolls 802 are moved (i.e., along the direction shown by the arrows 806,808), in order to change the relative distance between the three rolls.The bottom rolls 802 may be moved along sloped surfaces 810, 812, asshown in FIG. 8. As shown in the figures, the distance between eitherone of the bottom rolls 802 and the top roll 804 may change as thedistance between the bottom rolls 802 changes, because the bottom rolls802 are on sloped surfaces 810, 812 and the top roll 804 may be fixed.That is, in this example, the larger the distance between the bottomrolls 802, the smaller the distance between each bottom roll 802 and thetop roll 804. In one aspect (e.g., for a shallow slope), when the bottomrolls 802 are moved farther apart from each other, the stock of materialis given a lower amount of curvature as it passes between the rollers,and when the bottom rolls 802 are moved closer together the stock ofmaterial is given more curvature. The sloped surfaces 810, 812 may allowthe system to become less sensitive to errors in roll positioning—as thebottom rolls 802 move farther from each other they move closer to thetop roll 804, reducing the effect of their movement on the rolleddiameter relative to movement along a flat surface. In one aspect, itmay also be possible to have a steep enough slope such that moving thebottom rolls 802 away from each other makes the rolled diameter smaller,because with a steep slope the bottom rolls 802 do not get much fartheraway from each other but do get a lot closer to the top roll 804.

Sheet steering (i.e., steering the stock of material) will now bediscussed.

In general, sheet steering may be accomplished using components of theinfeed system and/or rolling assembly. In addition to control of thediameter of the tapered structure being formed, the system may alsoinclude a control for the infeed angle at which the stock of material isfed into the curving device. This can be accomplished in many ways. Ingeneral, at least two degrees of freedom should be present—that is, ittypically isn't sufficient to only control the infeed angle (e.g., witha system that can swing an infeed base, such as those in cylindricalspiral mills) without having control of the material position. Theimplementation illustrated in the figures included herein (see, e.g.,FIGS. 5A-B) uses a combination of an actuated drive system and steerablerollettes to achieve the desired infeed motion.

Sheet steering helps prevent gaps from forming in the tapered structure.An example of gaps in a tapered structure is shown in FIG. 9.Specifically, FIG. 9 shows a tapered structure 900 with gap errors 902,and a tapered structure 904 without gap errors.

In general, a piece of stock may be fed into the curving device (e.g.,triple roll) at the correct angle and position in order to form thedesired tapered structure without gaps or overlaps between turns. Asused in this disclosure, a skilled artisan will understand that “withoutgaps” (or the like) includes the stock having an intentional, controlledgap, e.g., for welding or the like. FIG. 10 shows an example of atapered structure 1000 formed by feeding the stock of material atdifferent angles. It is noted that FIG. 10 depicts a cylinder but itwill be referred to as a tapered structure 1000 because the principlesof FIG. 10 hold true for tapered structures as well as cylinders. Acylinder is only used for convenience to clearly illustrate therelationships discussed below (e.g., with a cylinder, a straight sheethas the same infeed angle, whereas for a tapered structure, the infeedangle varies as it's rolled, so the relationships below may not bevisible at particular instants using a tapered structure). FIG. 10 showsa tapered structure 1000 where the stock of material 1002 was fed intothe curving device at the correct angle, a tapered structure 1004 wherethe stock of material 1002 was fed into the curving device at too steepof an angle, and a tapered structure 1006 where the stock of material1002 was fed into the curving device at too shallow of an angle. Asshown by the tapered structure 1006 in FIG. 10, a relatively shallowinfeed angle may cause a piece of stock 1002 to wrap back on itself moretightly, possibly causing an overlap 1008. As shown by the taperedstructure 1004 in FIG. 10, a relatively steep infeed angle may cause thewrapped section of stock 1002 to be farther away, possibly resulting ina gap 1010 between corresponding edges 1012, 1014 of the stock 1002. Thecorrect infeed angle causes the stock 1002 to wrap into the desiredshape while maintaining the desired gap for joining edges of the stock(see tapered structure 1000 in FIG. 10). For a tapered structure, thisinfeed angle may vary as the stock is fed into the curving device. Someof the techniques described herein involve control systems that may varythe infeed angle (and other parameters described herein) such that theedges of the stock lie adjacent to each other, allowing them to bejoined (e.g., metal sheets with edges welded together) to form a desiredstructure 904, 1000, as shown in FIGS. 9 and 10, respectively.

A control system according to one aspect is able to vary the infeedangle by controlling the approach of the stock of material so that thestock is purely rotating (i.e., not translating) with respect to thepeak of the tapered structure as the stock is fed into the curvingdevice. This condition is equivalent to having each point on theincoming sheet of stock be at a constant distance from the peak of thetapered structure as the stock is fed into the curving device. However,the peak of the tapered structure itself might be moving relative toother parts of the system, as described more fully below. The purelyrotational condition described above concerns only the relative motionof the in-fed stock with respect to the peak's location. That is, boththe stock and the peak may also be translating or undergoing morecomplicated motion with respect to other components of the system. Ifthis condition is met, then even irregularly shaped stock can be joinedinto a tapered structure.

As discussed above, the infeed system may feed the stock material intothe curving device. An implementation includes an infeed control systemthat controls the feeding of the stock material into the curving deviceby controlling the infeed system. The infeed control system may controlvarious aspects of the stock of material being fed into the curvingdevice including, but not limited to, the infeed speed, the infeedangle, the direction of feeding material (e.g., into or out of thecurving device), the infeed force, the position of the stock ofmaterial, the position of various components of the infeed system, theoffset of components of the infeed system and/or the stock of material,and the like. In some implementations, the infeed system includes one ormore positioners, carriages, articulating arms, rollers, or the like,that feed each sheet of stock into the curving device, and each arecollectively controllable by the infeed control system to ensure thedesired infeed condition is met.

Turning back to FIGS. 5A and 5B, in some embodiments, the infeed system504 includes a drive system, which may include a drive roll 510 withinfeed rollers 512. The infeed rollers 512 can be individually driven bya drive system control system, which may be a component of the overallcontrol system or independent from other control systems. In particular,the infeed rollers 512 can be differentially driven by the drive systemcontrol system (e.g., with some infeed rollers 512 being driven at adifferent rate than other infeed rollers 512) so as to cause the stockto rotate as it passes through the infeed rollers 512. Controlling therotational speed of the infeed rollers 512 (in combination with otherparameters described herein) can help implement rotational motion of thestock of material 501 about the peak of truncated cone 502 to be formed.The infeed rollers 512 may be used together with a curving device withsteerable rollettes to steer the stock of material 501 in the desiredrotating manner.

In the embodiment shown in FIGS. 5A-B, the infeed system 504 is able totranslate along a direction parallel to the axis of the top roll 516(i.e., bend axis), and to rotate in the plane. The infeed system 504 maybe supported in the front (i.e., closer to the curving device 506) by aslewing ring (not shown; located behind stock of material 501 in FIG. 5Aand underneath the material in FIG. 5B) that is able to rotate freely.The slewing ring may in turn be supported by a bearing (also not shown;located behind stock of material 501 in FIG. 5A) that runs on a shaftthat may have an orientation that is parallel to the axis of the toproll 516. This may allow the infeed system 504 to both translate along adirection parallel to the axis of the top roll 516 and to rotate. Theinfeed system 504 may be supported in the rear (i.e., farther from thecurving device 506) by an air bearing 530 (or other low friction motiondevice) that supports the infeed system 504 while allowing it to bothrotate and translate with low friction.

In the embodiment shown in FIGS. 5A-5B, the position of the infeedsystem 504 can be controlled using at least two infeed actuators 514that act as infeed adjustment mechanisms (although other numbers andforms of positioners may be used). Together, the infeed actuators 514may be operable to set the position of the infeed system 504 along thex-axis and to set the angle of the infeed system 504, which may be doneunder the control of the infeed system control system. The infeedactuators 514 may include a hydraulic piston, pneumatic piston, servo,screw, actuator, rack and pinion, cable and pulley system, cam,electromagnetic drive, or other device capable of imparting the desiredmotion. Controlling the motion of the infeed system 504 via the infeedactuators 514 (in combination with other parameters described herein)can help implement rotational motion of the stock of material 501 aboutthe peak 503 of the truncated cone 502 during the construction process.

To assist in the control of the motion of the stock of material 501, theindividual rollettes 524 of the rollette banks 522 in the triple roll516 can be controlled in various ways. In some implementations, theindividual rollettes 524 can be steered by the control system. That is,the direction of motion imparted to the stock of material 501 by therollettes 524 is controllable by setting the angles of the individualrollettes 524 with respect to the chassis of the triple roll 516. Inparticular, the rollers can modify the motion imparted to the stock ofmaterial by the infeed system 504.

In some implementations, the rollettes 524 are fixedly mounted, but therotational speed of the rollers of the rollettes 524 is controllable. Insome implementations, controlling the relative speeds of the rollers ofthe rollettes 524 can collectively impart rotational motion of the stockof material 501 about the peak 503 of the truncated cone 502.

FIG. 11A depicts a system 1100 for sheet steering using a drive roll1102 and a bank 1104 of steerable rollettes 1106. Specifically, FIG. 11Ashows a schematic of a system 1100 by which a sheet of stock 1108 can begiven rotational motion 1110 using a system with a positionable drivesystem (e.g., positionable drive roll 1102) and steerable rollettes1106. The rolling directions for the rollettes 1106 are shown by thefirst arrows 1112 (where the rolling directions may be slightlydifferent for each rollette 1106), and the rolling direction for thedrive roll 1102 is shown by the second arrow 1114. Additionally, FIG.11A shows contact areas 1116 on the rollettes 1106 (i.e., where therollettes 1106 may contact the stock 1108, which may be a very smallarea, e.g., if the rollettes 1106 include rollers that are crowned), acontact area 1118 on the drive roll 1102 (i.e., where the drive roll1102 may contact the stock 1108), lines 1120 perpendicular to the firstarrows 1112 extending from the contact areas 1116 of the rollettes 1106,and lines 1122 perpendicular to the second arrow 1114 extending from thecontact area 1118 of the drive roll 1102. In an implementation, if thereis no (or negligible) slip, a sheet of stock 1108 will be driven alongthe rolling directions of all rolls in the system, including the driveroll 1102 and the individual rollettes 1106 (i.e., in the direction ofthe first and second arrows 1112, 1114). In general, it may only benecessary to have two non-parallel rolls to implement this system 1100.That is, when a single sheet of stock 1108 is acted on by twonon-parallel rolls, the only way it can move along the rollingdirections of both rolls without slipping is to rotate. In particular,the sheet of stock 1108 may rotate about the point 1124 located at theintersection of the lines 1120, 1122 that pass through the contact areas1116, 1118 and are perpendicular to the direction of rolling 1112, 1114,as shown in FIG. 11A. If more than two rollers are present in the system(e.g., the bank 1104 shown with multiple rollettes 1106) the rollersshould be positioned such that there is only one center of rotation, orelse slipping may occur at one or more rollers and the stock 1108movement will be poorly controlled. If two drive rolls 1102 are used asshown in FIG. 11B, the two drive rolls 1102 should also be positionedand their speeds controlled so that there is only one center of rotationat point 1124. In other words, if at least two drive rolls 1102 areused, the relative speeds of the drive rolls 1102 should be adjusted inorder to maintain rotation about a single point 1124. Specifically, thespeeds may be proportional to the distance of each drive roll 1102 fromthe axis of rotation. Also, the angles of the rollettes 1106 should becompatible with each other and with the drive rolls 1102, e.g., tomaintain rotation about a single point 1124. In general, the componentsof the system (which may include all components referenced in thisdocument) may be adjusted with the goal of having the stock of materialrotate more or less about a single point. In other words, it may not bepossible to perfectly align the stock of material and the components ofthe system (e.g., there may always be some slipping), so the componentsare adjusted in order to try to obtain optimal alignment where the stockof material rotates more or less about a single point.

The steering of the rollette banks may be accomplished, for example,with the cam plate steering described above with reference to FIGS. 3,4A and 4B.

The implementations herein use various structures—positioners, singlerollers, pairs or systems of rollers, etc.—to move the stock of materialor contribute to moving the stock of material such that the net resultis the stock of material moving rotationally with respect to the peak ofthe tapered structure as it moves through the curving device. Theseimplementations illustrate only a few of the virtually infinite numberof possibilities for accomplishing this result. In particular, theforegoing implementations do not exhaustively illustrate the full scopeof the invention. Moreover, even for a specific configuration ofequipment, in general there may be more than one way to control thevarious components so the net effect is to rotationally move the stockabout the peak of the tapered structure on the stock's way to thecurving device. Other control techniques are readily identifiable.

Implementations of a gap control system will now be described. “Gapcontrol system” as used throughout this disclosure shall refer to anycontrol system for correcting errors in the alignment of the edges ofthe stock of material when joining the edges of the stock of material,correcting gaps between the edges of the stock of material when joiningthe edges of the stock of material, and generally positioning themachinery and/or stock of material and/or tapered structure after thestock of material has been rolled through a portion of the curvingdevice.

Even if the stock of material is fed correctly through the curvingdevice (e.g., the bend roll in a triple roll), it may be beneficial tocorrect small errors in alignment and gap between corresponding edges ofthe stock of material after the edges are rolled and before they arejoined together. This could be due to discrepancies in the geometry ofthe sheets of stock material, e.g., due to tolerances in the materialforming processes, small errors in the infeed steering, small errors inthe rolling process, etc. It may be beneficial to have additionalsystems that address gap and alignment errors after rolling and prior tojoining edges of the stock of material together.

One of the purposes of the gap control system is to control the gap andalignment between a sheet of stock of material and thepartially-completed tapered structure as they are joined together. Forexample, there may be at least three errors to address: in-plane gaperror, out-of-plane gap error, and tangency alignment error. However,one skilled in the art will understand that the gap control system canbe used to address more or less errors, or any combination of same.

An example of in-plane gap error is illustrated in FIGS. 12A and 12B.FIG. 12A shows an example of a tapered structure 1200 (e.g., a truncatedcone) with no error, while the tapered structure 1200 in FIG. 12Bincludes a gap error. The first arrow 1201 in FIGS. 12A and 12B pointsto the same location, where there is an error in FIG. 12B at thislocation. The error may be an in-plane weld gap error 1202. In FIG. 12A,the gap 1204 is even and the stock of material 1206 to be joined (e.g.,welded) is aligned with the existing shape. In FIG. 12B, there is anin-plane gap error 1202, which means that, after joining is done at thislocation, the stock of material 1206 to be joined is disposed at anangle such that the gap is growing. An error also occurs if the gap isshrinking and is causing or will lead to an overlap and if the gap is“in the plane” of the existing curve—that is, the rolled material hasthe correct curvature to match the already-joined portion, but it's toofar away (or too close).

An example of out-of-plane gap error is illustrated in FIGS. 13A and13B. FIG. 13A shows an example with no error (FIGS. 13A and 13B depict acylinder 1300, rather than a cone, so that it is easier to see the errorwhen looking at the structure from an end). In FIG. 13A, the sectionshown viewed from an end looks like a complete circle because everythingon the cylinder 1300 is aligned. FIG. 13B depicts a cylinder 1300showing an example of an out-of-plane gap error 1302. The out-of-planegap error 1302 occurs because, after joining is done at this location,the stock of material 1306 to be joined is curving away from theexisting cylinder, opening up a gap 1304 that is out of the “plane” ofthe surface of the cylinder 1300 and causing ridges, bumps, dents (e.g.,curving in to cause a dent or the like), or other surface errors on thesurface of the tapered structure.

An example of tangency alignment error is illustrated in FIGS. 14A and14B. FIG. 14A shows an example of a tapered structure 1400 (e.g., atruncated cone) with no error, while the tapered structure 1400 in FIG.14B includes a tangency alignment error 1402. A tangency alignment error1402 does not necessarily involve a gap, but rather it may involve anerror in the alignment of the to-be-joined sheet surface 1404 with theexisting sheet surface 1406 in a tapered structure 1400. As depicted inFIG. 14B, this type of error occurs when there is a surfacemisalignment. In other words, if the error was allowed to remain and thesheets were joined into place, the final structure (e.g., wind turbinetower) would appear bent, or it would have a dent, bulge, or the like.

The gap and alignment may be measured close to the joining location,with the intent being that the measurement may be located at a distancethat is upstream of the joining such that adjustments can be made priorto joining. A method of measurement can include, but is not limited to,measuring with a laser line scanner (similar laser systems are used ingap-following automated welding systems), contact sensors (e.g., LVDTsor the like), a vision system using a video camera or similar, and soforth. It is also possible to measure the location of one of the edgesrelatively far away from the joining, for example, using a laser linescanner. In this case, only one edge may be measured, not a gap.

Implementations of a runout system will now be described. In general,gaps and misalignments may be corrected by translating and/or rotatingthe already-formed tapered structure relative to the rolled but notjoined sheet that is held in the curving device (e.g., triple roll). Todo this, one may either manipulate the rolled and joined taperedstructure, or the rolled but unjoined sheet. One possible way to do thismay be to hold the tapered structure in a runout system that supportsthe tapered structure after it has been joined, and to translate androtate the curving device as it holds the rolled but unjoined sheet.Another way to do this is may be to hold the curving device fixed, andto manipulate the rolled and joined tapered structure using the runoutsystem.

The runout system may have a number of mechanisms that are meant toprevent and/or correct the errors discussed herein. In an embodiment, arunout system has at least two subsystems—an “inboard” subsystem and an“outboard” subsystem. The inboard subsystem may be disposed close to thecurving device and joining element. The outboard subsystem may bedisposed close to the end of the tapered structure being formed, andsupport the end.

FIGS. 15 and 16 show an overview of an implementation of subsystems of arunout system, where FIG. 15 shows an inboard subsystem 1500 and FIG. 16shows an outboard subsystem 1600.

As shown in FIG. 15, the inboard subsystem 1500 may support the taperedstructure 1502 (e.g., truncated cone) as it is being formed, which mayprevent the triple roll 1504 from having to support its weight. Theinboard support mechanism 1506 may have an adjustable height, which canbe used to address an out-of-plane gap error or a tangency error. For anout-of-plane gap error, the inboard 1500 and outboard 1600 systems(which can also move up and down in an embodiment) may move up and downtogether, keeping the slope of the tapered structure 1502, 1602substantially the same but changing the out-of-plane gap. For a tangencyerror, the inboard 1500 and outboard 1600 systems may be movedvertically relative to each other, changing the angle of the taperedstructure 1502, 1602.

The inboard support mechanism 1506 may include supports, such as supportrollers 1508 or the like (e.g., pads, sliders, bearings, dampers, etc.).The support rollers 1508 may be positionable via a control (automatic ormanual) or they may be passive. The supports may include dampers or thelike, and they may be pivotable about a pivot point on a verticalsupport. The support rollers 1508 may allow the tapered structure 1502to rotate easily relative to the support rollers 1508. The supportrollers 1508 could be cylindrical, spherical (e.g., because the angle ofthe direction of the surface of the tapered structure 1502 relative tothe support rollers 1508 changes as the tapered structure 1502 diameterchanges, spherical rollers may account for this change), and the like.The supports may be disposed on a shaft 1510 or the like, where theshaft 1510 is movable from side to side (left and right). In addition,or in the alternative, the supports may be disposed on rails 1512, whichallow the support rollers 1508 or the like to move from side to side.For example, the shaft 1510 may include a ball screw or the like, wherethe support rollers 1508 are slidable along the rails 1512 and arepositioned by the ball screw. The position of the support rollers 1508along the ball screw may determine the height of the support rollers1508 and thus the height of the tapered structure 1502. This degree offreedom may also be used to passively adjust to changes in the positionof the tapered structure 1502 being formed. In addition, or in thealternative, a degree of freedom that may be used to passively adjust tochanges in position may be for the whole support structure 1506 movingfrom side to side on the rails 1512. The supports may move together, toadjust the position of the tapered structure 1502, or they may moverelative to each other, to adjust to the changing diameter of thetapered structure 1502 and/or to apply a force on the tapered structure1502. The supports may be passive, or they may include one or moreactuators or the like to control the side to side movement of thesupports. An actuator may be used to control the horizontal and/orvertical position of the tapered structure 1502 (e.g., in animplementation, if the supports are closer together, the taperedstructure 1502 is higher) by moving the supports relative to each other.The actuator may also or instead be used to control the left/rightposition of the tapered structure 1502 by moving the supports together.

As shown in FIG. 16, the outboard subsystem 1600 may support the end1604 of the tapered structure 1602, and may include mechanisms foraddressing the gap and alignment errors. Some of these mechanisms aredescribed below.

The outboard support 1606 of the outboard subsystem 1600 may move up anddown. This (in tandem with height adjustment of the inboard system 1500)can address an out-of-plane gap error. This movement can also be used toaddress a tangency error—for example, when the height of the inboardsystem 1500 is kept fixed, adjusting the height of the outboard support1606 may change the angle of the tapered structure 1502, 1602, so it canbe brought into alignment.

The outboard support 1606 of the outboard subsystem 1600 may move sideto side (perpendicular to the tracks 1608 shown in FIG. 16, i.e., leftand right). This movement can be used to correct an in-plane gap error.

The outboard support 1606 of the outboard subsystem 1600 may be used totorque or twist the tapered structure 1602 around its axis. Thistwisting is another method for correcting an out-of-plane error, i.e.,the twisting can be used to “wind-up” or “unwind” the to-be-joinedsheet, thereby changing its diameter and bringing it into alignment. Theoutboard subsystem 1600 may also have active control of its travel awayfrom the curving device as the tapered structure 1602 is being formed.For example, yet another possible degree of freedom is control of thetravel of the outboard cart 1610 along the tracks 1608. This controlcould potentially address in-plane gaps by moving the tapered structure1602 toward and away from the curving device which can open and closegaps. This movement can also provide a force on the tapered structure1602, which may be a pushing force toward the curving device or apulling force away from the curving device. The cart 1610 may alsoinclude a brake, which may be an actively controlled brake. Also, anembodiment may include a passive runout system. A skilled artisan willunderstand that the components of the outboard subsystem 1600 may beused to correct errors other than the errors specifically mentionedherein. For example, raising and lowering the outboard support 1606 cancorrect in-plane errors as well as out-of-plane errors. In addition,components of the other systems described herein may be used to correcterrors other than the errors specifically mentioned herein.

In an embodiment, the outboard support 1606 is disposed toward the end1604 of the tapered structure 1602 as shown in FIG. 16. However, inother embodiments, the outboard support may be disposed at otherlocations (not shown), including, but not limited to, toward the centerof the tapered structure or towards an end of the tapered structure thatis closest to the curving device.

The outboard support 1606 may include a vertical support post 1612 and ahorizontal support arm 1614, where the support post 1612 is engaged withthe cart 1610. At an end of the horizontal support arm 1614 there may bea cone engagement mechanism 1616, which includes a support structure forboth supporting the tapered structure 1602 and/or grabbing the taperedstructure 1602.

In an implementation, the cone engagement mechanism 1616 locks onto thetapered structure 1602 such that it can move and/or twist the taperedstructure 1200 without becoming disengaged. This may be accomplishedthrough a spindle or spindle-like structure, and/or using clamps, bolts,cables, clips, couplings, docks, dowels, a friction fit, gibs, hooks,joints, latches, locks, lugs, pins, screws, sliders, snaps, and thelike. For example, a grabber that supports the tapered structure 1602from the inside and allows it to rotate may be provided. The grabber maybe controlled to lock the tapered structure 1602, release the taperedstructure 1602, rotate the tapered structure 1602, and the like.

The outboard subsystem 1600 may include a cart 1610 that allows theoutboard subsystem 1600 to be mobile. The cart 1610 may include wheels1618 or the like that can ride along the tracks 1608 or the like. Animplementation may only include wheels 1618 or the like, without anytracks (not shown). The cart 1610 may also or instead include slides,which may slide along a track or slide freely (i.e., on the floor). Theslides may include a mechanism for decreasing sliding friction such aslow friction materials (e.g. Teflon), grease, rolling element bearings,air bearings, and the like.

Further implementations of a control system will now be discussed.

The construction systems described herein for forming a taperedstructure may include a control system that is able to control one ormore components of the construction system. For example, a controlsystem may include a sensor, or multiple sensors, that provide feedbackon a component or multiple components of the construction system and/oron the tapered structure being formed. The construction system mayinclude one or more adjustment mechanisms that can automaticallyposition a component or multiple components of the construction systemand/or the tapered structure being formed. Unless explicitly stated, orotherwise clear from the text, as used throughout this document, theadjustment of the stock of material, or the adjustment of the taperedstructure, shall include any adjustment to the material at any stageduring the construction of the tapered structure (before, during, orafter the formation of the tapered structure). The automatic positioningmay be based off of the feedback obtained from the sensors, and/or itmay be based off of a model used to form the desired tapered structure.For example, in an implementation that includes a triple roll, theadjustment mechanism may automatically position at least one of therolls of the triple roll to adjust the shape of a tapered structurebeing formed. The automatic positioning may allow for a substantiallycontinuous change in the diameter of the structure being formed suchthat it is tapered. The adjustment mechanism may include any means knownby skilled artisans, including without limitation hydraulic pistons,pneumatic pistons, servos, screws, actuators, rack and pinion systems,cable and pulley systems, cams, electromagnetic drives, robotic arms,rollers, drivers, or the like, or combinations of any of the foregoingor other device capable of imparting the desired motion.

The feedback from the sensors may be provided to a computer and/orcontroller, which may then send signals to an adjustment mechanism (ormultiple adjustment mechanisms) for automatically positioning thecomponents of the construction system, e.g., one of the rolls of thetriple roll. The feedback may include many different types of feedbackincluding, but not limited to, one or more of: a position of a componentof the construction system (e.g., one of the rolls of the triple roll,and/or a distance between at least two rolls of the triple roll, anangle of a component of the construction system relative to anothercomponent and/or the tapered structure being formed, and so on),geometric data of the tapered structure being formed (e.g., a diameter,a radius of curvature, a taper angle, an in-plane weld gap, anout-of-plane weld gap, an edge position, a distance of the “center” ofany a section of the tapered structure from an axis of the taperedstructure, and so on), force data (e.g., a force needed to complete anaction of the machine for forming a tapered structure, where the actionsinclude, but are not limited to, closing weld gaps, straightening thetapered structure for tangency, adjusting an angle of at least one ofthe plurality of rolls, moving at least one of the plurality of rolls,and driving a stock of material into or through the machine for forminga tapered structure), and the like.

The control system may further include a model for forming a taperedstructure. The model may be a mathematical and/or computer model. Themodel as described herein may include an empirical model (e.g., a purelyempirical model), a look-up table based on a model, a fundamentalconcepts model, or any combination of these models. The model outputsmay be based on theoretical or mathematical analysis, empiricalmeasurements, fitting factors, other factors, and/or other parametersthat may affect the machine operation. The model may compute resultsduring machine operation. The model may include previously computedresults that are stored and then accessed during machine operation. Themodel may include positions for one or more of the components of theconstruction system (e.g., the positions of the rolls included in thetriple roll). The model may also or instead include geometricinformation for the tapered structure being formed. The geometricinformation may include positions of coordinates and/or features of thetapered structure relative to one or more components of the constructionsystem and/or relative to each other. The model may include a model forideal edge positions of a stock of material, where the model includespositions of the curving device and the tapered structure based on thefeedback provided by an edge position sensor. The adjustment mechanismmay be configured to automatically position one or more components ofthe construction system (e.g., at least one roll of the triple roll)based on output from the model. The adjustment mechanism may also beconfigured to automatically position one or more components of theconstruction system based on a combination of the feedback from thesensors and the model.

The adjustment mechanism or mechanisms may be configured to position oneor more components of the construction system (e.g., at least one rollof the triple roll) along a sloped path. The adjustment mechanism ormechanisms may be configured to position one or more components of theconstruction system (e.g., at least one roll of the triple roll) along acurved path. The adjustment mechanism or mechanisms may be configured toposition an angle of one or more components of the construction system(e.g., at least one roll of the triple roll). The adjustment mechanismor mechanisms may be configured to position the tapered structure in anymanner as described herein or which would be reasonably apparent tothose of ordinary skill.

The construction system may include a triple roll, where the triple rollincludes three rollette banks, and the rollette banks include aplurality of individual rollettes, which may include rollers in animplementation. The adjustment mechanism may be configured to adjust anangle of a rollette bank. The adjustment mechanism may be configured toadjust an angle of the plurality of rollettes. Each individual rollettemay be capable of being steered, and adjustment mechanism or mechanismsmay be configured to do the steering.

The adjustment mechanism may be configured to position the rolls of thetriple roll independently. For example, multiple adjustment mechanismsmay be present, where each is configured to position a correspondingroll of the triple roll.

An implementation may include a stock of material for forming into thetapered structure, where the stock of material is fed into the machinefor forming a tapered structure and is formed into the tapered structureby the triple roll. The adjustment mechanism may be configured toautomatically adjust the angles of at least one set of rollettes tomaintain the stock of material in a proper position for forming into atapered structure. The adjustment mechanism may be configured toautomatically adjust the angle of at least one set of rollettes tocompensate for slipping of the stock of material.

In an implementation, the infeed system receives the stock material froma stock material source, a roll of stock sheets, a magazine of stock, orthe like, to the curving device. Thus, together, the infeed system andthe curving device may take a stock of material and curve the materialinto a desired shape, which may be a substantially conical shape with aradius that changes throughout its length. In an implementation, thecurving device includes a triple roll, where the triple roll includes atleast three rollette banks that include a plurality of rollettes. Thethree rollette banks of the triple roll may include at least two bottomrollette banks, where one acts as an inlet rollette bank and the otheracts as an outlet rollette bank. In an implementation, the inlet andoutlet rollette banks are able to move in order to control the shape ofthe material being formed. Controlling the shape of the material beingformed may be accomplished through controlling the diameter of thematerial being formed.

A control system of an implementation includes feedback, which may bebased upon any one of a number of criteria, or any combination ofcriteria. For example, the feedback may be based upon geometric data.The geometric data may be obtained from the shape being formed, whichmay be a tapered structure (e.g., a cone). The geometric data mayinclude, but is not limited to, a measurement of the diameter, radius ofcurvature, taper angle, weld gap (which may be a gap that is in theplane of the material being joined, or out of the plane, or both), and adistance of a section of the tapered structure from an axis of thetapered structure (which may be measured from the “center” of anysection to the axis). Any one of these measurements may be used, or anyother combination of these measurements may be used, as feedback for thecontrol system.

The feedback may also include geometric data from one or more of thecomponents of the curving device, including, but not limited to, therolls, the rollers, the rollette banks, the rollettes, the positioners,the wheels, the drive system, and so on. The feedback may also includegeometric data from one or more of the components of the infeed systemor runout system as described herein, or can be envisioned from thisdisclosure. This geometric data may also include relative data from onecomponent to another, for example, a distance between components, anangle between components, and the like.

In an implementation, the feedback may also or instead include forcedata. The force data may be obtained from the shape being formed, whichmay be a tapered structure (e.g., a cone). The force data may also orinstead include force data obtained from the components of theconstruction system. Examples of the force data include, but are notlimited to, forces that may be required to complete an action of theconstruction system for forming a tapered structure, such as the forcesneeded to close weld gaps, straighten the tapered structure fortangency, adjust the angle of a roll or rolls, move a roll or rolls,drive a material into or through the construction system, and the like.Any one or all of these forces may be used, or any other combination ofthese forces may be used as feedback for the control system.

In an implementation, the feedback data is obtained by sensors. Avariety of sensors may be usefully incorporated into the control systemsdescribed herein as will be readily apparent to one skilled in the art.For example, the sensors may include, but are not limited to, positionsensors (e.g., an edge position sensor), angle sensors, displacementsensors, distance sensors, speed sensors, acceleration sensors, opticalsensors, light sensors, imaging sensors, pressure sensors, forcesensors, torque sensors, level sensors, weight sensors, proximitysensors, presence (or absence) sensors, magnetic sensors, radio sensors,acoustic sensors, vibration sensors, and the like. The sensors mayinclude a singular sensor or numerous sensors.

The sensors may also include an imaging device and image processingcircuitry to capture an image of the tapered structure being formed orcomponents of the construction system and analyze the image to evaluatethe shape, position, etc. of the tapered structure being formed orcomponents of the construction system. The sensors may also or insteadinclude at least one video camera. The video camera may generallycapture images of the construction system and/or the tapered structurebeing formed. The video camera may provide a remote video feed through anetwork interface, which feed may be available to operators through auser interface maintained by, e.g., remote hardware such as a server orwithin a web page provided by a web server.

The construction system may include a sensor that detects a position ofthe stock of material along the path of construction (from the infeedsystem, to the curving device, to the runout system) or the position atany area of the system.

The sensors may also include more complex sensing and processing systemsor subsystems, such as a three-dimensional scanner using opticaltechniques (e.g., stereoscopic imaging, or shape from motion imaging),structured light techniques, or any other suitable sensing andprocessing hardware that might extract three-dimensional informationfrom the constructions system and/or tapered structure. In anotheraspect, the sensors may include a machine vision system that capturesimages and analyzes image content to obtain information, e.g., thestatus of a tapered structure being formed. The machine vision systemmay support a variety of imaging-based automatic inspection, processcontrol, and/or robotic guidance functions for the construction systemincluding without limitation pass/fail decisions, error detection (andcorresponding audible or visual alerts), shape detection, positiondetection, orientation detection, collision avoidance, and so forth.

In an embodiment, a sensor provides feedback that includes the radius ofthe tapered structure being formed. The construction system may then becontrolled by the control system to maintain a substantially continuousradius adjustment in the tapered structure in order to form asubstantially cone shaped object. In other words, the radius adjustmentmay be automatically controlled in order to create a constantly changingdiameter, as would be done for a tapered shape.

An implementation includes adjustable triple roll banks for rollingtapered cones. An implementation includes substantially continuouslyadjusting the machinery, which may include adjusting the triple rollbank, during the rolling process in order to substantially continuouslyadjust the diameter of a tapered structure being formed. The diameter ofthe tapered structure being formed may be varied by moving the rolls,where moving the rolls may be a reaction to the changing diameter.

An embodiment may include controlling the angles of the rollettesthemselves. A triple roll for forming a tapered structure may includerollette banks that are comprised of multiple individual rollers orrollettes. These rollette banks may replace the rollers in aconventional roll bending process. The heading angles of individualrollettes can be steered in an implementation, and the rollettes in animplementation are actively and continuously steered thus providingcontinuous control over stock motion. In an implementation, therollettes also serve to steer the material as it passes through thetriple roll.

The rollette angle may be controlled for the following reasons. Thetriple roll (interfacing with the stock of material/sheet through therollettes) is one of the means for controlling the bulk motion of theincoming feed stock and formed tapered structure. By steering therollettes (alone, or in conjunction with other modules) in anappropriate manner, the incoming feed stock carries out a specificmotion for rolling tapered structures.

In an embodiment, rollettes can be steered to control weld gap. In anembodiment, rollettes can be steered to shift the stock towards or awayfrom the throat of the triple roll to maintain proper sheet positionwithin the triple roll. Rollettes may also be steered to compensate forside slip.

The rollettes may be steered individually with electric motors, gears,racks, cams, linkages, screws, chains, belts, hydraulics, pneumatics,magnetically, manually, friction drives, traction drives, thermally, andthe like.

All or some of the rollettes on a bank of rollettes may be steeredtogether but through angles individual to each rollette. Specifically,in an implementation, for rollettes driven together, each individualrollette angle corresponds to a particular, but not the same, angle forall the other rollettes. These rollette groups may be steered withmotors, gears, racks, cams, linkages, screws, chains, belts, hydraulics,pneumatics, magnetically, manually, friction drives, traction drives,thermally, and the like.

All or some of the rollettes on a particular rollette bank may besteered all together through the same angles. These rollette groups maybe steered with motors, gears, racks, cams, linkages, screws, chains,belts, hydraulics, pneumatics, magnetically, manually, friction drives,traction drives, thermally, and the like.

In an implementation, the rollettes on a particular rollette bank may besteered using a cam plate as described above. The cam plate may havedifferent profiles for each cam, resulting in different motions for eachrollette, or the same profiles for one or more cams, resulting in thesame steering motion for the corresponding rollettes. The profiles inthe cam plate may correspond to the desired rollette motions (based on amodel) for rolling a particular cone. Or, the profiles may correspond toanother relationship between the cam plate position and rollette anglesthat allows the control system to adjust the rollette angles, i.e.,there could be a linear relationship (moving the cam a certain distancecauses the rollette heading angle to change proportionally), etc.

In an implementation, one or all of an infeed positioning system,curving device positioning system, and a runout positioning system maybe used to control the distance and angle between two correspondingedges of the stock as the edges are joined. In an implementation, theformed and joined tapered structure is held fixed in the runout system,and the curving device, along with the section of stock that is held inthe curving device, is positioned relative to the formed and joinedstructure. The curving device may be translated relative to the formedand joined structure, in order to close in-plane gaps between edges ofthe stock so that they can be joined. The curving device may also rotaterelative to the formed and joined structure, e.g., in order to closeout-of-plane gaps and correct tangency mismatches between edges.

FIG. 17 shows a flow chart 1700 for a method for weld gap adjustmentaccording to an implementation.

As shown in step 1702, the method may include feeding a stock ofmaterial into and through a curving device. The feeding of the stock ofmaterial may be accomplished through any of the means described herein,including, without limitation an infeed system that may include a driveroll and an infeed adjustment mechanism. The curving device may includea triple roll.

As shown in step 1704, the method may include detecting the position ofthe stock of material. This may include detecting at least one edge ofthe stock of material. The detection may be made by a sensor.Additionally or alternatively, this step may include detecting theposition of a component of the infeed system or curving device.

As shown in step 1706, the method may include determining whether theposition indicates an undesirable gap condition. This step may includesending the position to a gap error controller, where the controllerdetermines whether the position indicates an undesirable gap condition.The determination may also be accomplished by comparing thesensed/detected position to a known ideal position, where the knownideal position may be part of a model, a known measurement, apredetermined value, a position from previous operations of the systemor method. The undesirable gap position may be any of the errorsdescribed herein, e.g., an inconsistency in a weld gap, an angularalignment error, a planar alignment error, etc.

If an undesirable gap position is detected, the method may proceed tostep 1708, and if an undesirable gap position is not detected, themethod may skip to step 1712.

As shown in step 1708, the method may include sending adjustmentinstructions to a gap adjustment mechanism. The adjustment instructionsmay be sent by a controller, e.g., the gap error controller. Theadjustment instructions may include a position of a component of thesystem (e.g., the infeed system or the curving device), a position ofthe stock of material, a position or movement of an adjustmentmechanism, and the like. The gap adjustment mechanism may be anyadjustment mechanism described herein (or combination thereof) that canadjust a component of the systems described herein including, withoutlimitation, an infeed adjustment mechanism, a drive roll adjustmentmechanism, a rollette steering mechanism, a runout adjustment mechanism,and so on. In other words, the adjustment instructions may compensatefor the positioning error. For example, the positioning error mayinclude an inconsistency in a weld gap included in the stock ofmaterial, and the adjustment instructions may include instructions toposition the stock of material such that a consistent weld gap is formedduring the welding of the stock of material. The positioning error mayinclude a planar alignment error in the stock of material, and theadjustment instructions may include instructions to position the stockof material such that an edge of the stock of material is substantiallyadjacent to an opposing edge of the stock of material as they arejoined. The positioning error may include an angular alignment errordetected in the stock of material, and the adjustment instructions mayinclude instructions to position the stock of material such that an edgeof the stock of material is substantially parallel with an opposing edgeof the stock of material as they are joined.

As shown in step 1710, the method may include positioning the stock ofmaterial with the gap adjustment mechanism. This step may include any ofthe positioning components, systems, and methods described herein.

As shown in step 1712, the method may include joining the stock ofmaterial using the joining elements. This may include joiningcorresponding edges of the stock of material together, for example,using a welder. The joining may include substantially continuouslyjoining the stock of material as it is rolled through the curvingdevice, or after it is rolled through the curving device and into arunout system to form a tapered structure in the runout system.

FIG. 18 shows a block diagram for a control system 1800 according to animplementation. Specifically, FIG. 18 shows a machine 1802, which may bea machine for forming a tapered structure, a computer 1804, which mayinclude a model 1806, and a controller 1808.

The machine 1802 may include a curving device 1810, an adjustmentmechanism 1812, a joining element 1814, an infeed system 1816, a runoutsystem 1818, and at least one sensor 1820.

The curving device 1810 may be any described herein, e.g., a tripleroll. The triple roll may have at least three rolls including at leastone bend roll and at least two guide rolls. The guide rolls may includerollette banks having a plurality of rollettes.

The adjustment mechanism 1812 may be any means for adjustment describedherein, and it may be suitable for adjusting any component of themachine 1802, e.g., a component of the curving device 1810 (e.g., one ormore of the rolls of the triple roll). In an implementation including atriple roll, the adjustment mechanism 1812 may be configured to positionat least one of the rolls, where a diameter of a tapered structure beingformed is controlled by relative positions of the rolls. The adjustmentmechanism 1812 may be configured to translate at least one of the rollsin a triple roll relative to another one of the rolls without changingan angle of the roll in order to substantially continuously adjust thediameter of the tapered structure being formed. The adjustment mechanism1812 may also or instead be configured to position an angle of at leastone of the rolls with respect to another one of the rolls in a tripleroll. The adjustment mechanism 1812 may include numerous adjustmentmechanisms, e.g., one adjustment mechanism configured to position acorresponding roll in a triple roll. The adjustment mechanism 1822 maybe configured to position the stock of material such that the stock ofmaterial rotates about a peak of the tapered structure or an end of thetapered structure.

The joining element 1814 may be any described herein, e.g., a welder.The joining element 1814 may be controllable and movable.

The infeed system 1816 may include its own adjustment mechanism 1822(e.g., an infeed adjustment mechanism configured to position a stock ofmaterial as it is fed into the curving device), or it may use theadjustment mechanism 1812 described above. The infeed system 1816 mayinclude any of the components described herein, e.g., a drive roll. Theinfeed system 1816 may also include at least one edge roller 1824configured to constrain positions of edges of a stock of material fedinto or through the curving device 1810, where the adjustment mechanism1822 is configured to position the edge roller 1824.

The runout system 1818 may include its own adjustment mechanism 1826, orit may use the adjustment mechanism 1812 described above. The runoutsystem 1818 may include any of the components described herein, e.g.,any of the components associated with the inboard subsystem 1828 and theoutboard subsystem 1830.

The sensor 1820 may be any sensor described herein, and the sensor 1820may be part of the machine 1802 or a separate component. The sensor 1820may provide feedback to the controller 1808, which may use the feedbackto send control signals to components of the machine 1802. The feedbackmay include geometric data of the tapered structure being formed, wherethe geometric data includes, without limitation, a diameter, a radius ofcurvature, a taper angle, a weld gap, a distance of a section of thetapered structure from an axis of the tapered structure, and the like.The feedback may also or instead include force data, including, withoutlimitation, a force needed to complete an action, where the actionincludes at least one of: closing weld gaps, straightening the taperedstructure for tangency, adjusting an angle of one of the rolls in atriple roll, moving a roll, and driving the stock of material into orthrough the machine for forming a tapered structure.

The model 1806 may be any model described herein, and the model 1806 maybe disposed on or implemented by the computer 1804. Alternatively, themodel 1806 may be stored on or implemented by the controller 1808, or aprocessor associated with the controller 1808. The model 1806 may sendinformation to the controller 1808, which may use the information tosend control signals to components of the machine 1802. The model 1806may generally include a model for forming a tapered structure thatincludes, without limitation, relative positions of the rolls of atriple roll for desired tapered structure diameters, relative positionsof the stock of material as it is fed into or through the machine forforming a tapered structure, and the like.

The controller 1808 may send control signals to one or more componentsof the machine 1802 based on the feedback from the sensor 1820 alone,the information from the model 1806 alone, information from more thanone sensor or model, or any combination thereof. The controller 1808 maybe configured to receive the feedback from the sensor 1820. Thecontroller 1808 may also be configured to send a control signal based onthe feedback to any of the components of the system 1800, e.g., theadjustment mechanisms 1812, 1822, 1826 for positioning a component ofthe machine 1802 or a stock of material being formed into a taperedstructure.

The controller 1808 may be electrically or otherwise coupled in acommunicating relationship with one or more components of the system1800. The controller 1808 may include any combination of software and/orprocessing circuitry suitable for controlling the various components ofthe system 1800 described herein including without limitationmicroprocessors, microcontrollers, application-specific integratedcircuits, programmable gate arrays, and any other digital and/or analogcomponents, as well as combinations of the foregoing, along with inputsand outputs for transceiving control signals, power signals, sensorsignals, and so forth. In one aspect, this may include circuitrydirectly and physically associated with the components of the system1800, such as a processor. In another aspect, this may be a processor,which may be associated with a personal computer or other computingdevice coupled to the components of the system 1800, e.g., through awired or wireless connection. Similarly, various functions describedherein may be allocated between a controller, processor, and a separatecomputer. All such computing devices and environments are intended tofall within the meaning of the term “controller” or “processor” as usedherein, unless a different meaning is explicitly provided or otherwiseclear from the context.

FIG. 19 shows a method 1900 for controlling the formation of a taperedstructure.

As shown in step 1902, the method 1900 may include sensing an attributewith a sensor on a system for forming a tapered structure. The attributemay be a geometric attribute of the tapered structure being formed, ageometric attribute of the system for forming a tapered structure, aforce attribute of the tapered structure being formed, a force attributeof the system for forming a tapered structure, and the like, or anycombination thereof. The sensor may include any sensor described hereinor otherwise known by a skilled artisan.

The system for forming a tapered structure may include a curving device,which may be a triple roll having at least three rolls including atleast one bend roll and at least two guide rolls, where the guide rollsinclude rollette banks having a plurality of rollettes. The system forforming a tapered structure may further include an adjustment mechanismconfigured to position at least one of the rolls, where a diameter ofthe tapered structure being formed is controlled by relative positionsof the rolls. The system for forming a tapered structure may furtherinclude a joining element for joining edges of a stock of materialtogether as the stock of material is rolled through the curving device(e.g., the triple roll) to form the tapered structure.

As shown in step 1904, the method 1900 may include sending feedback fromthe sensor to a controller. The feedback may be based on the sensedattributes discussed above. The controller may be any discussed hereinor otherwise known by a skilled artisan. The controller may be remote tothe system or integral with the system. The feedback may be sent to thecontroller via a sensor signal, and the feedback may beprocessed/analyzed at the controller or at another location/device.

As shown in step 1906, the method 1900 may include sending adjustmentinstructions to the adjustment mechanism. The adjustment instructionsmay be sent from the controller, or from another component of thesystem. The adjustment instructions may be based on the feedback. Theadjustment mechanism may be any of the adjustment mechanisms discussedherein, i.e., capable of adjusting a position of the stock of material(including the tapered structure before, during, and after formation),and/or a component of the system/machine for forming a taperedstructure.

As shown in step 1908, the method 1900 may include adjusting a positionof a roll. This may include adjusting a position of at least one of therolls of the triple roll, or any component of the curving device, withthe adjustment mechanism based on the adjustment instructions.

FIG. 20 shows a method 2000 for controlling the formation of a taperedstructure.

As shown in step 2002, the method 2000 may include sensing a position ofa stock of material with a sensor on a system for forming a taperedstructure. The stock of material may be the stock for forming into atapered structure or the tapered structure itself (including the taperedstructure before, during, and after formation).

The system for forming a tapered structure may be similar to thatdescribed herein, for example with reference to FIG. 19, and may also orinstead include an infeed adjustment mechanism configured to positionthe stock of material as it is fed into at least one of the rolls, thestock of material forming the tapered structure as it is rolled throughthe curving device. The infeed adjustment mechanism may include anymeans for adjusting any component of the infeed system, including thestock of material, or moving another component of the system therebypositioning the stock of material as it is fed into the curving device.

As shown in step 2004, the method 2000 may include sending feedback fromthe sensor to a controller. The feedback may be based on the position ofthe stock of material.

As shown in step 2006, the method 2000 may include sending adjustmentinstructions to the infeed adjustment mechanism. The adjustmentinstructions may be sent from the controller, or from another componentof the system. The adjustment instructions may be based on the feedback.

As shown in step 2008, the method 2000 may include adjusting a positionof the stock of material. This may include adjusting a position of thestock of material as it is fed into or through the system for forming atapered structure based on the adjustment instructions.

FIG. 21 shows a method 2100 for controlling the formation of a taperedstructure.

As shown in step 2102, the method 2100 may include sensing a position ofan edge of a stock of material with an edge position sensor. The stockof material may be the stock for forming into a tapered structure or thetapered structure itself (including the tapered structure before,during, and after formation). The system for forming a tapered structuremay include a rolling assembly, a joining element, a runout system, andan adjustment mechanism.

As shown in step 2104, the method 2100 may include sending feedback fromthe edge position sensor to a controller. The feedback may be based onthe position of the edge of the stock of material.

As shown in step 2106, the method 2100 may include sending adjustmentinstructions to the adjustment mechanism. The adjustment instructionsmay be sent from the controller, or from another component of thesystem. The adjustment instructions may be based on the feedback.

As shown in step 2108, the method 2100 may include adjusting a positionof the tapered structure (e.g., before, during, or after formation).This may include adjusting a position of the tapered structure relativeto the rolling assembly using the adjustment mechanism based on theadjustment instructions, e.g., after the stock of material has beenthrough the rolling assembly.

FIG. 22 shows a method 2200 for forming a tapered structure.

As shown in step 2202, the method 2200 may include sensing, with asensor, sensor data. The sensor data may include at least one of: ageometric attribute of the tapered structure being formed, a geometricattribute of a machine component, a force attribute of the taperedstructure being formed, a force attribute of a machine component, aposition of the stock of material, a position of a machine component, aninconsistency in a weld gap in the stock of material, a planar alignmenterror in the stock of material, and an angular alignment error in thestock of material. The sensing may take place at any step during themethod shown 2200, and adjustments at any step may be made based in thesensor data.

As shown in step 2204, the method 2200 may include sending feedback fromthe sensor to a controller. The feedback may be based on the sensordata.

As shown in step 2206, the method 2200 may include sending adjustmentinstructions to the adjustment mechanism. The adjustment instructionsmay be sent from the controller, or from another component of thesystem. The adjustment instructions may be based on the feedback.

As shown in step 2208, the method 2200 may include adjusting a positionof the stock of material using the adjustment mechanism based on theadjustment instructions. Adjusting the position of the stock of materialmay include the adjustment mechanism positioning at least one of: theinfeed system, the at least three rolls, the runout system, and thetapered structure being formed.

As shown in step 2210, the method 2200 may include driving a stock ofmaterial with an infeed system. The infeed system may be any of theinfeed systems described herein.

As shown in step 2212, the method 2200 may include feeding the stock ofmaterial through a rolling assembly. The rolling assembly may be anydescribed herein, for example, a triple roll including at least threerolls with at least one bend roll and at least two guide rolls. Theguide rolls may include rollette banks having a plurality of rollettes.

As shown in step 2214, the method 2200 may include joining edges of thestock of material together as the stock of material is rolled throughthe rolling assembly to form a tapered structure. The joining mayutilize a joining element as described herein.

As shown in step 2216, the method 2200 may include guiding the stock ofmaterial out of the rolling assembly with a runout system. The runoutsystem may be any of the runout systems described herein.

The control systems described herein include control systems directed tothe entire construction system, or a portion thereof, including withoutlimitation the infeed system, the curving device, the joining element,and the runout system. As used throughout this disclosure “controlsystem” shall refer to a control system for any and all of theaforementioned systems, or combinations thereof, unless a particularcomponent/machine is expressly required or otherwise clear from thecontext.

In the foregoing, the terms “machinery” and “component” refer to anelement, or a combination of elements, of the construction system asdescribed herein unless otherwise stated or clear from the context.These terms may also refer to the construction system as a whole.

The above control systems, devices, methods, processes, and the like maybe realized in hardware, software, or any combination of these suitablefor the control, data acquisition, and data processing described herein.This includes realization in one or more microprocessors,microcontrollers, embedded microcontrollers, programmable digital signalprocessors or other programmable devices or processing circuitry, alongwith internal and/or external memory. This may also, or instead, includeone or more application specific integrated circuits, programmable gatearrays, programmable array logic components, or any other device ordevices that may be configured to process electronic signals. It willfurther be appreciated that a realization of the processes or devicesdescribed above may include computer-executable code created using astructured programming language such as C, an object orientedprogramming language such as C++, or any other high-level or low-levelprogramming language (including assembly languages, hardware descriptionlanguages, and database programming languages and technologies) that maybe stored, compiled or interpreted to run on one of the above devices,as well as heterogeneous combinations of processors, processorarchitectures, or combinations of different hardware and software. Atthe same time, processing may be distributed across devices such as thevarious systems described above, or all of the functionality may beintegrated into a dedicated, standalone device. All such permutationsand combinations are intended to fall within the scope of the presentdisclosure.

Embodiments disclosed herein may include computer program productscomprising computer-executable code or computer-usable code that, whenexecuting on one or more computing devices, performs any and/or all ofthe steps of the control systems described above. The code may be storedin a non-transitory fashion in a computer memory, which may be a memoryfrom which the program executes (such as random access memory associatedwith a processor), or a storage device such as a disk drive, flashmemory or any other optical, electromagnetic, magnetic, infrared orother device or combination of devices. In another aspect, any of thecontrol systems described above may be embodied in any suitabletransmission or propagation medium carrying computer-executable codeand/or any inputs or outputs from same.

It will be appreciated that the methods and systems described above areset forth by way of example and not of limitation. Numerous variations,additions, omissions, and other modifications will be apparent to one ofordinary skill in the art. In addition, the order or presentation ofmethod steps in the description and drawings above is not intended torequire this order of performing the recited steps unless a particularorder is expressly required or otherwise clear from the context.

The meanings of method steps of the invention(s) described herein areintended to include any suitable method of causing one or more otherparties or entities to perform the steps, consistent with thepatentability of the following claims, unless a different meaning isexpressly provided or otherwise clear from the context. Such parties orentities need not be under the direction or control of any other partyor entity, and need not be located within a particular jurisdiction.

Described herein are systems, methods, and devices for constructing atapered structure, and control systems and methods for same. It will beunderstood that while the exemplary embodiments herein emphasize theconstruction of a tapered structure and controls for same, theprinciples of the invention may be adapted to other fabricationprocesses. All such variations that can be adapted to use the systems,methods, and devices as described herein are intended to fall within thescope of this disclosure.

Other components of the control system may also be included, such asinput devices including a keyboard, touchpad, mouse, switches, dials,buttons, and the like, as well as output devices such as a display, aspeaker or other audio transducer, light emitting diodes, and the like.Other hardware may also or instead include a variety of cableconnections and/or hardware adapters for connecting to, e.g., externalcomputers, external hardware, external instrumentation or dataacquisition systems, and the like.

The control systems may include, or be connected in a communicatingrelationship with, a network interface. The network interface mayinclude any combination of hardware and software suitable for couplingthe control system and construction system to a remote computer in acommunicating relationship through a data network. By way of example andnot limitation, this may include electronics for a wired or wirelessEthernet connection operating according to the IEEE 802.11 standard (orany variation thereof), or any other short or long range wirelessnetworking components or the like. This may include hardware for shortrange data communications such as Bluetooth or an infrared transceiver,which may be used to couple into a local area network or the like thatis in turn coupled to a data network such as the Internet. This may alsoor instead include hardware/software for a WiMax connection or acellular network connection (using, e.g., CDMA, GSM, LTE, or any othersuitable protocol or combination of protocols). Consistently, thecontrol system may be configured to control participation by theconstruction system in any network to which the network interface isconnected.

In the foregoing, various tasks have been described that involverelative motion of various components. However, it is recognized thatvarying design constraints or other practical considerations may callfor certain components to remain fixed (relative to the ground) or toundergo only minimal motion. For example, the construction system can bedesigned such that any one or more of the following components remainsfixed relative to the ground: the source of stock material, any desiredcomponent of the feed system, any desired component of the curvingdevice, any desired component of the welder, any desired component ofthe runout system, the peak/top/end of the tapered structure underconstruction, etc. Similarly, the system can be designed such that noneof the above components remain fixed relative to the ground (or, exceptas noted above, relative to each other). In some implementations, theheaviest or hardest to move component remains fixed relative to theground. In some implementations, the relative motion of the componentsis chosen to best mitigate the risk of injury to those near the system.In some implementations, the relative motion of the components is chosento maximize the expected life of the system as a whole or the expectedlife of one or more components.

While particular embodiments have been shown and described, it will beapparent to those skilled in the art that various changes andmodifications in form and details may be made therein without departingfrom the spirit and scope of this disclosure and are intended to form apart of the invention as defined by the following claims, which are tobe interpreted in the broadest sense allowable by law.

1. A control system for forming a tapered structure comprising: a sensorproviding feedback for a machine for forming a tapered structure, themachine for forming a tapered structure comprising: at least three rollsincluding at least one bend roll and at least two guide rolls, the atleast two guide rolls including rollette banks comprising a plurality ofrollettes; an adjustment mechanism configured to position at least oneof the at least three rolls, wherein a diameter of the tapered structurebeing formed is controlled by relative positions of the at least threerolls; and a joining element configured to join edges of a stock ofmaterial together as the stock of material is rolled through the atleast three rolls to form the tapered structure; and a controllerconfigured to receive the feedback from the sensor, the controllerfurther configured to send a control signal based on the feedback to theadjustment mechanism for positioning the at least one of the at leastthree rolls.
 2. The control system of claim 1 wherein the adjustmentmechanism is configured to translate the at least one of the at leastthree rolls relative to another one of the at least three rolls withoutchanging an angle of the at least one of the at least three rolls inorder to substantially continuously adjust the diameter of the taperedstructure being formed.
 3. The control system of claim 1 wherein theadjustment mechanism is configured to position an angle of the at leastone of the at least three rolls with respect to another one of the atleast three rolls.
 4. The control system of claim 1 wherein the feedbackcomprises geometric data of the tapered structure being formed, thegeometric data including at least one of: a diameter, a radius ofcurvature, a taper angle, a weld gap, and a distance of a section of thetapered structure from an axis of the tapered structure.
 5. The controlsystem of claim 1 wherein the feedback comprises force data.
 6. Thecontrol system of claim 5 wherein the force data includes a force neededto complete an action, the action including at least one of: closingweld gaps, straightening the tapered structure for tangency, adjustingan angle of the at least one of the at least three rolls, moving the atleast one of the at least three rolls, and driving the stock of materialinto or through the machine for forming a tapered structure.
 7. Thecontrol system of claim 1 further comprising a model for forming atapered structure, the model comprising relative positions of the atleast three rolls for desired tapered structure diameters.
 8. Thecontrol system of claim 7 wherein the adjustment mechanism is configuredto automatically position the at least one of the at least three rollsbased on a combination of the feedback from the sensor and the model. 9.The control system of claim 1 wherein the adjustment mechanism isconfigured to position the at least one of the at least three rollsalong at least one of a sloped path or a curved path.
 10. The controlsystem of claim 1 further comprising a plurality of adjustmentmechanisms, each configured to position a corresponding one of the atleast three rolls. 11-18. (canceled)
 19. A control system for forming atapered structure comprising: an edge position sensor configured toprovide feedback including a position of an edge of a stock of materialto be formed into a tapered structure in a machine for forming a taperedstructure, the machine for forming a tapered structure comprising: arolling assembly comprising a plurality of rolls; a joining elementconfigured to join edges of the stock of material together as the stockof material is rolled through the rolling assembly to form the taperedstructure; a runout system configured to support the tapered structureafter the edges are joined; and an adjustment mechanism configured toposition the tapered structure relative to the rolling assembly; and acontroller configured to receive the feedback from the edge positionsensor, the controller further configured to send a control signal basedon the feedback to the adjustment mechanism to achieve a desiredrelative movement between portions of the tapered structure.
 20. Thecontrol system of claim 19 wherein the runout system comprises asubsystem providing support to the tapered structure by engaging aportion of the tapered structure, the subsystem comprising at least oneactuator configured to position the tapered structure.
 21. The controlsystem of claim 19 wherein the rolling assembly is movable relative toother components of the machine for forming a tapered structure, whereinthe tapered structure is held by the runout system, and wherein therolling assembly is configured to be moved relative to the runout systemto achieve the desired relative movement between portions of the taperedstructure.
 22. The control system of claim 19 wherein the feedbackcomprises an inconsistency in a weld gap included in the stock ofmaterial, and wherein the control signal is configured to adjust theposition of at least one of the rolling assembly and the taperedstructure such that a consistent weld gap is formed while joining theedges of the stock of material together.
 23. The control system of claim19 wherein the feedback comprises a planar alignment error in the stockof material, and wherein the control signal is configured to adjust theposition of at least one of the rolling assembly and the taperedstructure such that the edge of the stock of material is substantiallyadjacent to an opposing edge of the stock of material as they arejoined.
 24. The control system of claim 19 wherein the feedbackcomprises an angular alignment error detected in the stock of material,and wherein the control signal is configured to adjust the position ofat least one of the rolling assembly and the tapered structure such thatthe edge of the stock of material is substantially parallel with anopposing edge of the stock of material as they are joined.
 25. Thecontrol system of claim 19 further comprising a model for ideal edgepositions, the model comprising positions of the rolling assembly andthe tapered structure based on the feedback provided by the edgeposition sensor, wherein the control signal is at least partially basedon the model.
 26. (canceled)
 27. A control system for forming a taperedstructure comprising: a model for use in a machine for forming a taperedstructure, the machine for forming a tapered structure comprising: atleast three rolls including at least one bend roll and at least twoguide rolls, the at least two guide rolls including rollette bankscomprising a plurality of rollettes; an infeed adjustment mechanismconfigured to position a stock of material as it is fed into the atleast three rolls, the stock of material forming the tapered structureas it is rolled through the at least three rolls; and a joining elementconfigured to join edges of the stock of material together as the stockof material is rolled through the at least three rolls to form thetapered structure, wherein the model comprises relative positions of thestock of material as it is fed into or through the machine for forming atapered structure; a computer configured to implement the model; and acontroller configured to receive instructions based on the model, thecontroller further configured to send a control signal based on theinstructions to the infeed adjustment mechanism for positioning thestock of material.
 28. A method for controlling the formation of atapered structure comprising: sensing with a sensor, on a system forforming a tapered structure, at least one of a geometric attribute ofthe tapered structure being formed and a force attribute of the taperedstructure being formed, the system for forming a tapered structurecomprising: at least three rolls including at least one bend roll and atleast two guide rolls, the at least two guide rolls including rollettebanks comprising a plurality of rollettes; an adjustment mechanismconfigured to position at least one of the at least three rolls, whereina diameter of the tapered structure being formed is controlled byrelative positions of the at least three rolls; and a joining elementconfigured to join edges of a stock of material together as the stock ofmaterial is rolled through the at least three rolls to form the taperedstructure; sending feedback from the sensor to a controller, thefeedback based on at least one of the geometric attribute and the forceattribute; sending adjustment instructions from the controller to theadjustment mechanism, the adjustment instructions based on the feedback;and adjusting a position of at least one of the at least three rollswith the adjustment mechanism based on the adjustment instructions.29-32. (canceled)